Deer Exclosure

Jeff's Nature Home Page

Linda Chorice of the Springfield Conservation Nature Center pointed me to a story on a deer exclosure on NPR.  Exclosure refers to the eight foot high fencing used keep deer out of an area.  Although this could be used to protect plants or gardens, this particular exclosure was created to study the habitat changes brought on by a heavy population of deer.

Whitetail deer were a daily sight when Henry Rowe Schoolcraft traversed southern Missouri in 1818.  There were also numerous wolves, bear and even panther which served as predators to keep the deer population in balance, and a whole country for them to roam and browse.  In current times their primary predators (hunters and vehicles) haven't kept them in check.

The deer habitat has changed with agriculture and hay fields taking over past forests and savannas.  Browsing opportunities have been somewhat limited so they nibble a higher percent of new young trees in the islands of woodlands surrounded by fields.  Meanwhile they have adapted quite well to the more urban life where they are relatively free from hunting pressure.  They have developed a more sophisticated taste in dining including table decorations and salads, i.e. flowers and vegetable gardens.

Urban Deer- Outdoorcentral.com

The NPR story highlights the habitat changes seen by excluding deer from 10 acres. There was considerably more diversity in the protected area with a wider variety of forbs and shrubs as well as young trees.  This provided for more favorable habitat for mice and chipmunks which are a natural part of the food chain for snakes, foxes, etc.

There are two small exclosures along the trails at the Springfield Conservation Nature Center.  Next time you pass by, stop and check out any differences between the plants inside and outside the fence. You may notice a relative absence of new growth trees and shrubs outside as deer browse tender young shoots.  Without a chance to develop young trees, we end up with open woods lacking the habitat needed by many small mammals.   As the trees age and die, there are no young and teenage trees to take their place.  Deer also browse the shrubs which produce berries that feed birds and too many for this urban island of nature eliminates this food source for birds.

The effects of too many deer living on this protected urban island doesn't threaten the survival of birds and our forests.  It simply highlights the more widespread effects as habitat is consumed by human activities and deer numbers increase in the absence of natural predators.  Hunting controls the population in the wild.  In our expanding urban areas...not so much.

MSU conducts studies of the flora in and outside of the exclosure at the Nature Center. Take time to compare this with the surrounding woods at the Nature Center the next time you walk the trails.

* Checkout Jeff's Nature Home Page to view some of his incredible nature photography.